Poinsettia plant named `603`

ABSTRACT

Poinsettia `603` is a new cultivar, distinguished by dark red flower bracts, dark green foliage, self-branching characteristics, compact upright growth habit and 8-week flowering response time. The new plant produces a very desirable branched flowering pot plant for early to mid-season holiday market. Poinsettia `603` is resistant to epinasty after being confined to shipping containers. The post-production foliage and bract retention are excellent even under low light intensities in the consumer&#39;s home.

BACKGROUND OF THE NEW PLANT

The new poinsettia cultivar, `603`, originated as an inducedself-branching sport of a seedling known as `H-62` (not patented) in mygreenhouse in Encinitas, Calif. It was selected because of its dark,rich red flower bracts, dark green foliage, self branchingcharacteristics, and upright growth habit; traits that distinguish itfrom other poinsettia cultivars, and seem to make it a desirable plantfor commercial greenhouse production. After selection, `603` wasvegetatively reproduced from stem cuttings for test purposes inEncinitas, Calif. `H-62` is a proprietary plant and there are nospecimens in the public domain. Poinsettia `H-62` is not self-branchingin that no axillary branches develop as long as the apical bud is notremoved (pinched). `603` is self-branching in that during developmentaxillary branches elongate without removal of the apical bud. Undershort day conditions, the axillary branches will develop flowers.

Poinsettia `603` most closely resembles poinsettia `409` (U.S. PlantPat. No. 7,825), but differs in these aspects: `603` has a more compactand upright growth habit and fewer cyathia than `490` under the samecultural conditions. By subjecting clones of this plant to successivegenerations of vegetative propagation, it was demonstrated that thedistinctive characteristics of `603` held true from generation togeneration.

DESCRIPTION OF THE PHOTOGRAPHS

Poinsettia `603` is illustrated in the accompanying color photographs.

FIG. 1 is a side view of a branched `603` plant, left, compared toanother dark leafed cultivar `490`, right, in full flower.

FIG. 2 is a top view of the same `603` plant showing flower and bractformation.

DESCRIPTION OF THE PLANT

The following is a detailed description of this new poinsettia asobserved in Encinitas, Calif. USA during Dec. 1994. Observations wererecorded from flowering plants, grown as one branched plant per pot. Thepot was 14 cm in diameter and 11 cm in height. Color designations arecompared to the 1986 edition of R.H.S. Colour Chart, first published in1966 by The Royal Horticultural Society, London, England.

THE PLANT

The following chart summarizes some of the differences betweenPoinsettia `603` and the plant it most closely resembles, Poinsettia`490` (U.S. Plant Pat. No. 7,825) under the same cultural conditions.

    ______________________________________                                        Plant          `603`        `490`                                             ______________________________________                                        Overall height 38 cm        43 cm                                             Overall width  35 cm        45 cm                                             Bract diameter 24 cm        30 cm                                             Leaf dimensions                                                                              12 × 8 cm                                                                            14 × 10 cm                                  No. of Bracts  10-12        16-18                                             Bract dimensions                                                                             14 × 9 cm                                                                            17 × 10 cm                                  Bract color    RHS 46A-B    RHS 45A                                           No. of cyathia 4-5          14-15                                             ______________________________________                                    

Origin: Sport of a seedling. The sport was induced by application of theprocedures set forth in U.S. Pat. No. 4,724,276, incorporated herein byreference, to the seedling plant. Root stock used was `Annette Hegg DarkRed` (U.S. Plant Pat. No. 3,160).

Classification:

Botanical.--Euphorbia pulcherrima Willd.

Common name.--Poinsettia.

Cultivar name.--`603`.

Form: Shrub.

Height: Short.

Growth habit: Single stemmed plant, upright and vigorous withself-branching side shoots. The application of a chemical growthretardant may not be needed to restrict height for commercial pot plantproduction. I observed a branched plant in a pot with an overall heightof 38 cm and an overall width of 35 cm. The bract diameter of individualflowers was 24 cm.

Branching: Axillary branches will develop and terminate in a flowerwithout pinching. However, it is usually desirable to pinch `603` beforeflower induction and remove all terminal dominance. Then, all axillarybranches will develop uniformly and at a faster rate.

Growth rate: Rooting of stem cutting occurs in 12-18 days underintermittent mist. The plant will flower in about eight weeks undercontinuous long night conditions and night temperatures of about 16-18degrees C.

Foliage: The foliage is clean and uniformly dark green from bottom totop of the plant. The leaves are of medium size, leaf blades typically12 cm long and 8 cm wide with leaf petioles 4 cm long and deep red. Theupper leaf surface is glabrous and the under surface is finelypubescent.

Leaf shape.--Typical leaves are generally ovate with acute to obtusebases and acuminate tips. Leaf margins are lobed with 1 or 2indentations on each side of the leaf blade.

Color.--Upper side -- Dark green, darker than R.H.S. 147A. Under side --Green, near R.H.S. 147A.

Retention.--The foliage lasts extremely well even under low lightintensities in the consumer's home.

Bracts: Generally there are 10-12 rich red bracts of various sizessubtending the cyathia. The primary bracts have blades typically 14 cmlong and 9-10 cm wide with petioles about 2 cm long.

Shape.--Primary bracts are ovate with acute bases and acuminate tips.Primary bract margins are entire or modestly lobed with 1 or 2indentations on either side of the bract. Secondary bracts are ofvarious sizes, ovate to elliptical, slightly rugose and have entiremargins.

Color.--Upper side -- Rich, dark red, between R.H.S. 46A-B. Under side-- Red, R.H.S. 46B-53B.

Flowers: Generally, 4-5 cyathia (flowers) are present when the plant isin full bloom. Each cyathium is about 6 mm long and 5 mm wide, green incolor, and fringed with red at the distal end. A yellow nectar cupprotrudes from the side of each cyathium. The flower pedicel is alsogreen and about 5 mm in length. The stamens protruding from the cyathiaare dark red. The anthers are bifurcate; the pollen is yellow andcopious. The stigmas are dark red and trifurcate.

Nectar exudate.--Abundant.

Seeds.--Self-incompatible.

Fertility.--Not observed.

Post production: Poinsettia `603` is resistant to epinasty after beingconfined to shipping containers and retains its leaves and flower bractsfor several weeks in the consumer's home environment.

What is claimed is:
 1. A new and distinct cultivar of Poinsettia plant,substantially as herein shown and described, distinguished by its darkred flower bracts, dark green foliage, self-branching characteristicsand compact upright growth habit.